What serous membrane protects the heart, lungs and abdominal cavity?

After reading the paragraph below, answer the questions that follow. researchers have created a robot that has a very thin leg that is moved by cardiac (heart) cells contracting in unison. the robot, made of a polymer similar to that used in making contact lenses, is bathed in heart cells with supporting cells, which then attach to the robot and provide movement as they contract. all of the cardiac cells working together can cause the robot leg to move in a way that individual cells could not. this is an example of a. emergent properties of cells. b. energy flow through an ecosystem. c. adaptation. d. internal environment regulation.

I've created a synthetic cellular membrane that is made up of phospholipids, but contains no proteins. which of the types of movements across a membrane would not function with my synthetic membrane?

Can an organism fill more than one trophic level?